February Nature Almanac: Redpolls invade Colorado

Common redpolls have irrupted into Colorado this winter and come readily to feeders.
(Photo by Bill Schmoker)

Other February events

Bohemian waxwings have also irrupted our way this winter. A northern cardinal has been scrabbling in the brush a short distance up from the end of Hawthorn Avenue for almost two months. And tundra swans continue to hang out at Valmont Reservoir. It's a good year for nomadic birds in Colorado.

Bluebirds usually arrive by the end of the month. Resident great-horned owls and golden eagles nest.

Raccoons mate in February and March and may usurp your chimney as a nursery.

Mourning cloak and Milbert's tortoiseshell butterflies may emerge from crevices behind bark on warm days to feed on oozing sap.

Candlemas, halfway between the winter solstice and the vernal equinox, is celebrated on Feb. 2 (also Groundhog Day) to honor the strengthening light and the stirrings of passion and new growth.

Common redpolls, birds of the Arctic that are not at all common in Colorado, have been irrupting far south of the Canadian border this winter.

Excited birders throughout the northern United States have been reporting huge redpoll numbers since November. Flocks of more than 40 individuals have been flitting around Boulder County, often converging on a field or a feeder and then quickly zipping away.

Advertisement

Although a redpoll sighting in Boulder County is a rare treat, Cornell ornithologists estimate their numbers worldwide to be in the tens of millions. These members of the finch family nest in the boreal regions of both the Old and the New World where they eat insects as well as seeds.

Abundant in Alaska and Canada, common redpolls can withstand temperatures of minus-65 degrees and sometimes tunnel into the snow to roost during frigid nights. But when spruce cones and birch, willow and alder catkins are scarce, redpolls often head more than 1,000 miles south of their normal wintering grounds searching for food.

These spiffy birds look like tiny sparrows wearing raspberry-red forehead patches and tiny black bibs around their bills. Dark brown streaks decorate their flanks, and males often display a pinkish wash on the breast. Even females sport a spot of red on the head. Redpolls often flock with goldfinches and tree sparrows, similar-sized birds with similar feeding habits.

If you see an unusually pale redpoll, look closely. It might be the even more uncommon hoary redpoll. Common redpolls (Carduelis flammea) and hoary redpolls (C. horneman) are listed as separate species, but it can be difficult to distinguish a light common redpoll from a dark hoary. In addition, there are, arguably, six subspecies.

Flocks of these fluttery, frenetic songbirds can suddenly descend on a food source -- weeds, willows, birch, conifers or grass -- and just as quickly zip away again. The acrobatic birds sometimes hang upside down to glean the seeds, which they store in throat pouches. Then they disperse into dense cover to regurgitate and digest the food in safety.

Redpolls come readily to feeders, seeming to prefer thistle and millet. Their constant buzzy chatter may alert you to their presence.

In the past few weeks, redpolls have foraged in trees and shrubs around Lagerman Reservoir, Baseline Reservoir, Fawn Brook Inn near Allenspark, in Ward and at many private feeders. More than 200 were reported around the county during the Christmas bird count.

The largest, most reliably seen flock has been feeding regularly at the Museum of Discovery in Fort Collins. This flock of more than 100 includes a few hoary redpolls.

Ruth Carol Cushman and Stephen Jones are authors of "Wild Boulder County" and "The North American Prairie."

Boulder is pretty good at producing rock bands, and by "rock," we mean the in-your-face, guitar-heavy, leather-clad variety — you know, the good kind. For a prime example, look no farther than BANDITS. Full Story